Poly(iso)quinolinediyls and preparation and use thereof

ABSTRACT

An (iso)quinolinediyl polymer having a degree of polymerization of at least 5 is produced from an (iso)quinoline dihalide by a reaction with a zero-valent nickel compound, or an electrolytic reduction in the presence of a nickel compound. Since it is excellent in heat-resistivity and soluble in organic solvents, this polymer can be shaped by a dry-process into fibers, films or the like. Its depolarization degree and electrochemical oxidation-reduction potential can be controlled according to its structure.

This is a division of application Ser. No. 07/848,193 filed Mar. 10,1992, pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to polyquinolinediyls orpolyisoquinolinediyls [hereinafter collectively referred to as"(iso)quinolinediyl polymers"] soluble in organic solvents, andexcellent in heat-resistivity and electrochemical activity, comprising,as a recurring structural unit, a divalent residue of a condensedheterocyclic compound, quinoline or isoquinoline [hereinaftercollectively referred to as "(iso)quinoline"], derived by eliminatingtwo hydrogen atoms therefrom, and manufacturing processes and usesthereof.

2. Description of the Prior Art

Polyarylenes having a structure comprising continuous linkages ofaromatic rings, such as poly-p-phenylene, poly-2,5-thienylene andpoly-1,4-naphthylene, generally have an excellent heat-resistivity.Besides, it has been known that adducts of these polyarylenes with anelectron acceptor such as AsF₅ or the like or an electron donor such aslithium, sodium or the like have an electroconductivity and propertiesutilizable as active materials for primary cells or secondary batteries[for example, "High Molecules", vol. 34, p. 848 (1985)]. Alternatively,there are proposed in Japanese Patent Application Laid-open No.1-210,420 electroconductive materials produced by reducing a polymercomprising, as a recurring structural unit, a group comprising a6-membered heterocyclic unit containing a π-conjugation system extendingcontinuously along the polymer main chain, for example, 2,5-pyridinediylgroup.

However, since most of the hitherto proposed polyarylenes have a lowsolubility in organic solvents and are infusible, their use is limitedand, moreover, problems are posed in drawing out their characteristicfunctions. Further, it has been desired to develop novel polymers withphysical properties the aforementioned conventional polyarylenes havenever possessed, by modifying the molecular structures thereof. Forexample, if polyarylenes different in oxidation-reduction potential fromthe conventional polyarylenes can be obtained, polymer batteriesdiffering in characteristics from the conventional batteries [forexample, described in "Denki Kagaku" vol. 54, p. 306 (1986)] will beable to be provided by using these novel polyarylenes as a component ofbatteries such as an electrochemically active material or electrodematerial.

SUMMARY OF THE INVENTION

The present invention has been accomplished, under these circumstances,as a result of assiduous studies conducted aiming to find polyaryleneshaving a novel molecular structure.

An object of the present invention is to provide novel polyarylenes,particularly (iso)quinolinediyl polymers, having an excellentheat-resistivity, being soluble in organic solvents and having acontrollable degree of depolarization and electrochemicaloxidation-reduction potentials.

Another object of the present invention is to utilize such novel(iso)quinolinediyl polymers as shaped bodies such as fibers, films orthe like; electrochromic elements; components for cells, such as activematerials, electrodes or the like, of cells; n-type semiconductors; orthe like.

The above objects can be achieved by (iso)quinolinediyl polymerscomprising, as a recurring structural unit, a divalent group representedby the following chemical formula (1) or (2): ##STR1## which is derivedfrom a condensed heterocyclic compound, (iso)quinoline, by eliminatingtwo hydrogen atoms at arbitrary positions thereof, and having a degreeof polymerization (n) of at least 5. If the degree of polymerization (n)is less than 5, sufficient performances as a polymer will not be able todisplay. Further, the present inventors have so far confirmed actuallythrough experiments the polymers of the present invention having adegree of polymerization (n) of as high as about 200, prepared accordingto the after-described electrolytically reducing polycondensationprocess, and excellent properties and usefulness thereof. However,preparation and usefulness of polymers having a degree of polymerizationexceeding about 200 can be naturally expected from the technical pointof view.

The above-described polymers can be prepared by reacting an(iso)quinoline dihalide represented by the following general formula (3)or (4): ##STR2## wherein X represents a halogen atom, with a zero-valentnickel compound. The above (iso)quinoline dihalides shown in the generalformula (3) or (4) are derivatives of (iso)quinoline substituting twohydrogen atoms in arbitrary positions thereof with halogen atoms

Alternatively, the above polymers also can be prepared byelectrolytically reducing the (iso)quinoline dihalide compounds shown bythe formula (3) or (4) in the presence of a nickel compound.

The novel (iso)quinolinediyl polymers according to the present inventioncan be applied to fibers, films, electrochromic elements or componentsof cells, such as active materials or electrodes of cells, by utilizingexcellent characteristics thereof, and can be utilized as n-typesemiconductors after reducing these polymers by means of a reducingagent or an electrochemical doping.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent from reading the followingdescription of the preferred embodiments taken in connection with theaccompanying drawings, wherein:

FIG. 1 is a diagram showing IR spectra of the polymers according to thepresent invention; and

FIG. 2 is a diagram showing a ¹³ C-NMR spectrum of an embodiment of thepolymer according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In this specification, the term "polyarylene" is meant by a polymercomprising an aromatic ring as a recurring structural unit, such aspoly-p-phenylene or poly-1,4-naphthylene, and the term "aromatic ring"is understood to include heterocyclic rings such as pyridine, thiopheneor the like, in addition to aromatic hydrocarbon rings such as a benzenering.

The (iso)quinolinediyl polymers according to the present invention canbe obtained by reacting an (iso)quinoline dihalide, for example,(iso)quinoline chloride or bromide, with an equimolar amount or excessof a zero-valent nickel compound added thereto in an organic solvent,followed by dehalogenation. A preferable reaction temperature rangesbetween room temperature and about 80° C. The reaction completes withinabout 24 hours. As the above organic solvent, for example,N,N-dimethylformamide, acetonitrile, toluene, tetrahydrofuran or thelike can be employed.

The zero-valent nickel compound withdraws halogens from halogenatedaromatic compounds and causes a coupling reaction between the aromaticgroups [for example, "Synthesis", p. 736 (1984)]. This reaction isrepresented by the following equation (5):

    Ar--X+Ar'--X+NiL.sub.m →Ar--Ar'+NiX.sub.2 L.sub.m   (5)

wherein Ar and Ar' represent an aromatic group, X represents a halogenatom, L represents a neutral ligand and hence NiL_(m) represents azero-valent nickel compound.

Accordingly, if an aromatic compound having two halogens in themolecule, such as (iso)quinoline dihalide, is reacted with an equimolaror excess of a zero-valent nickel compound, the polymer of the presentinvention can be obtained by the dehalogenation polycondensationreaction shown in the following equations (6) and (7):

    2·X--Ar"--X+NiL.sub.m →X--Ar"--Ar"--X+NiX.sub.2 L.sub.m (6)

    X--(Ar").sub.n1 --X+X--(Ar").sub.n2 --X+NiL.sub.m→X--(Ar").sub.n1+n2 --X+NiX.sub.2 L.sub.m                                     (7)

wherein X--Ar"--X represents an (iso)quinoline halide and X represents ahalogen.

In the above-described reaction, as the zero-valent nickel compound,those synthesized in a reaction system, so to speak, in situ,immediately before conducting a polymerization reaction can be useddirectly. Alternatively, preliminarily synthesized and isolated onesalso can be used. Such a zero-valent nickel compound is, for example, anickel complex produced by a reduction reaction or a ligand interchangereaction in the presence of a neutral ligand. As a typical example ofthe neutral ligand, mention may be made of 1,5-cyclooctadiene,2,2'-bipyridine, triphenylphosphine or the like.

Alternatively, the (iso)quinolinediyl polymers shown in the chemicalformula (1) or (2) ca be obtained by another process wherein the(iso)quinoline dihalide shown in the above chemical formula (3) or (4)undergoes a dehalogenation reaction when it is subjected to anelectrolytic reduction reaction in the presence of a divalent nickelcompound. Namely, when a divalent nickel compound is electrolyticallyreduced in an electrolytic cell, a zero-valent nickel compound isproduced by the reaction shown in the following chemical formula (8).

    [Ni.sup.II L.sub.m ].sup.2+ +2e→Ni.sup.O L.sub.m    (8)

Accordingly, when an aromatic compound having two halogens in themolecule, namely, an (iso)quinoline dihalide is electrolytically reducedin the presence of a divalent nickel compound, the polymer shown in thechemical formula (1) or (2) can be obtained according to the reactionshown in the chemical formula (8) and the reactions shown in thefollowing formulae (9)-(11) consequently taking place, wherein theNi^(O) L_(m) producing in the reaction system is involved.

    Ni.sup.O L.sub.m +X--Ar"--X→X--Ni.sup.II L.sub.m --Ar"--X (9)

    2·X--Ni.sup.II L.sub.m --Ar"--X+2e→X--Ar"--Ar"--X+Ni.sup.O L.sub.m +2X.sup.-                                         (10), and ##STR3## wherein X--Ar"--X represents an (iso)quinoline dihalide, where X is a halogen.

The electrolysis may be conducted generally in the following conditions:namely, N,N-dimethylformamide or acetonitrile is used as a solvent,tetraethylammonium perchlorate or tetraethylammonium tetrafluoroborateas a supporting electrolytic salt is dissolved to prepare an electrolyteand a platinum electrode, ITO transparent electrode or graphiteelectrode is employed as an electrode. The (iso)quinoline dihalide anddivalent nickel complex are dissolved in the electrolyte and theelectrolytic reduction is conducted at a reduction potential of thedivalent nickel complex, for example, at -1.7V vs Ag/Ag⁺ in the case oftris(2,2-bipyridine)-nickel salt.

The above nickel compounds which have been synthesized and isolatedprior to the polymerization reaction can be used. Alternatively, thosesynthesized from nickel or a nickel compound in an electrolytic cell canbe used directly as they are in the cell. As such a nickel compound,mention may be made of, for example, tris(2,2'-bipyridine)nickeldibromide [Ni(bpy)₃ Br₂ ], dibromobis(triphenylphosphine)nickel [NiBr₂(PPh₃)₂ ] or the like.

The present invention will be explained more concretely and detailedlyby way of example hereinafter.

EXAMPLE 1

A 44 mmol anhydrous bis(acetylacetonate)nickel [referred to as"Ni(acac)₂ "] and a 114.8 mmol 1,5-cyclooctadiene were dissolved in a100 ml toluene. Forty ml of a 65.6 mmol triethylaluminum toluenesolution were dropped into and reacted with the above solution tosynthesize a zero-valent nickel complex, i.e.,bis(1,5-cyclooctadiene)nickel [referred to as "Ni(cod)₂ "]. ThisNi(cod)₂ was recrystallized from toluene.

A 4 mmol Ni(cod)₂ was dissolved in a 30 ml N,N-dimethylformamide, thenadmixed with 4 mmol of 1,5-cyclooctadiene and 2,2'-bipyridine, andfurther admixed with a 4 mmol 5,8-dibromoquinoline. The resultingmixture was reacted at a reaction temperature of 60° C. for 24 hours. Bythis reaction, a reddish-yellow, powdery quinoline-5,8-diyl polymer wasobtained. This powdery polymer was isolated by filtering and then, inorder to remove impurities such as nickel compounds or the liketherefrom, washed several times each with the under-enumeratedsubstances (a)-(f), sequentially in this order.

(a) a 29% ammonia aqueous solution,

(b) methanol,

(c) a sodium ethylenediamine tetraacetate hot aqueous solution, adjustedto pH 3,

(d) a 29% ammonia aqueous solution,

(e) hot water, and

(f) methanol.

After having finished the above washing, the powdery polymer was driedusing a vacuum line. Elemental analysis values of the resulting polymerwere found to be: 84.3% carbon, 4.0% hydrogen, 10.9% nitrogen and 0.0%bromine and almost agreed with calculated values of a polymer comprisingthe recurring structural unit represented by the following chemicalformula (12) ##STR4##

The calculated values are: 85.0% carbon, 3.9% hydrogen and 11.6%nitrogen. The difference between the found and calculated values seemsto be attributable to the difficulty in achieving a complete combustionwhen performing the elemental analysis of the polymer, mainly due to ahigh heat-stability of the polymer. In this example, the yield of thepolymer was 92%.

The above polymer was soluble in formic acid. Therefore, the molecularweight of the polymer was determined by the light scattering method withregard to a formic acid solution of the polymer. As the result, it wasfound that the polymer had a weight-average molecular weight of 11,000corresponding to a degree of polymerization of about 87.

In addition, the infrared absorption spectrum of the above polymershowed the below-described absorptions.

3,028 m, 1,623 m, 1,577 s, 1,498 vs, 1,456 m, 1,375 s, 1,354 m, 1,235 w,1,197 w, 1,150 m, 1,054 m, 945 vs, 838 s, 788 vs, 679 m, 499 w, 419 w,where the numbers indicate positions of absorption in a cm⁻¹ number, andw, m, s and vs mean weak absorption, medium absorption, strongabsorption and very strong absorption, respectively. The above resultsof the measurements were obtained all in a KBr pellet.

Additionally, the UV to visible region spectrum of a formic acidsolution of the above polymer showed relatively sharp, clear andmountain-like maximal absorption peaks in the vicinity of about 345, 320and 260 nm.

Furthermore, the above polymer exhibited a high heat-stability. As aresult of thermogravimetric analyses, a slight weight loss was observedfor the first time at about 300° C. Upon heating up to 900° C. innitrogen, the ignition loss was about 18% by weight.

EXAMPLE 2

A pale yellow, powdery, quinoline-4,7-diyl polymer was obtained in thesame manner as Example 1, except that 4,7-dichloroquinoline was used inlieu of 5,8-dibromoquinoline. This powdery polymer was isolated byfiltering and then, in order to remove impurities such as nickelcompounds or the like therefrom, washed several times each with theunder-enumerated substances (a)-(f), sequentially in this order.

(a) a 29% ammonia aqueous solution,

(b) methanol,

(c) a sodium ethylenediamine tetraacetate hot aqueous solution, adjustedto pH 3,

(d) a 29% ammonia aqueous solution,

(e) hot water, and

(f) methanol.

After having finished the above washing, the powdery polymer was driedusing a vacuum line. Elemental analysis values of the resulting polymerwere found to be: 83.5% carbon, 4.2% hydrogen, 10.9% nitrogen and 0.0%bromine and almost agreed with calculated values (85.0% carbon, 3.9%hydrogen and 11.6% nitrogen) of a polymer comprising the recurringstructural unit represented by the following chemical formula (13)##STR5##

The difference between the found and calculated values seems to beattributable to the difficulty in achieving a complete combustion whenperforming the elemental analysis of the polymer, mainly due to a highheat-stability of the polymer. In this example, the yield of the polymerwas 98%.

The above polymer was soluble in formic acid and a chloroform solution.Therefore, the molecular weight of the polymer was measured by means ofthe gel permeation chromatography (GPC) with regard to a chloroformsolution of the polymer. As the result, it was found that the polymerhad a number-average molecular weight of 7,900 corresponding to a degreeof polymerization of about 62.

In addition, the infrared absorption spectrum of the above polymershowed the below-described absorptions.

3,042 m, 1,614 s, 1,577 s, 1,558 s, 1,490 m, 1,450 w, 1,444 m, 1,411 m,1,373 w, 1,292 w, 1,186 w, 1151 w, 1,057m, 953 w, 892 s, 824 vs, 796 m,781 s, 683 s, 613 m, 452 w, where the numbers indicate positions ofabsorption in a cm⁻¹ number, and w, m, s and vs mean weak absorption,medium absorption, strong absorption and very strong absorption,respectively. The above results of the measurements were obtained all ina KBr pellet.

Additionally, the UV to visible region spectrum of a formic acidsolution of the above polymer showed relatively sharp, clear andmountain-like maximal absorption peaks in the vicinity of about 340 and280 nm.

Furthermore, the above polymer exhibited a high heat-stability. As aresult of thermogravimetric analyses, a slight weight loss was observedfor the first time at about 320° C. Upon heating up to 900° C. innitrogen, the rate of the ignition loss was about 17% by weight.

EXAMPLE 3

A bright yellow, powdery, quinoline 2,6-diyl polymer was obtained in thesame manner as Example 1, except that 2,6-dichloroquinoline was used inlieu of 5,8-dibromoquinoline. This powdery polymer was isolated byfiltering and then, in order to remove impurities such as nickelcompounds or the like therefrom, washed several times each with theunder-enumerated substances (a)-(f), sequentially in this order.

(a) a 29% ammonia aqueous solution,

(b) methanol,

(c) a sodium ethylenediamine tetraacetate hot aqueous solution, adjustedto pH 3,

(d) ammonia water,

(e) hot water, and

(f) methanol.

After having finished the above washing, the powdery polymer was driedusing a vacuum line. Elemental analysis values of the resulting polymerwere found to be: 84.8% carbon, 4.0% hydrogen, 11.1% nitrogen and 0.0%chlorine and almost agreed with calculated values (85.0% carbon, 3.9%hydrogen and 11.6% nitrogen) of a polymer comprising the recurringstructural unit represented by the following chemical formula (14)##STR6## The difference between the found and calculated values seems tobe attributable to the difficulty in achieving a complete combustionwhen performing the elemental analysis of the polymer, mainly due to ahigh heat-stability of the polymer. In this example, the yield of thepolymer was approximately 100%.

The above polymer was soluble in formic acid. Therefore, the molecularweight of the polymer was determined by the light scattering method withregard to a formic acid solution of the polymer. As the result, it wasfound that the polymer had a weight-average molecular weight of 15,000corresponding to a degree of polymerization of about 118.

In addition, the infrared absorption spectrum of the above polymershowed the below-described absorptions.

3,050 m, 1,583 s, 1,548 m, 1,476 s, 1,456 m, 1,355 w, 1,294 w, 1,192 s,1,130 m, 1,058 s, 882 s, 828 vs, 771 w, 658 m, 481 m, where the numbersindicate positions of absorption in a cm⁻¹ number, and w, m, s and vsmean weak absorption, medium absorption, strong absorption and verystrong absorption, respectively. The above results of the measurementswere obtained all in a KBr pellet.

Additionally, the UV to visible region spectrum of a formic acidsolution of the above polymer showed relatively sharp, clear andmountain-like maximal absorption peaks in the vicinity of about 436, and293 nm.

Furthermore, the above polymer exhibited a high heat-stability. As aresult of thermogravimetric analyses, a slight weight loss was observedfor the first time at about 170° C. Upon heating up to 900° C. innitrogen, the ignition loss was about 28% by weight.

EXAMPLE 4

A pale yellow, powdery, isoquinoline-1,4-diyl polymer was obtained inthe same manner as Example 1, except that 1,4-dibromoisoquinoline wasused in lieu of 5,8-dibromoquinoline. This powdery polymer was isolatedby filtering and then, in order to remove impurities such as nickelcompounds or the like therefrom, washed several times each with theunder-enumerated substances (a)-(f), sequentially in this order.

(a) a 29% ammonia aqueous solution,

(b) methanol,

(c) a sodium ethylenediamine tetraacetate hot aqueous solution, adjustedto pH 3,

(d) a 29% ammonia aqueous solution,

(e) hot water, and

(f) methanol.

After having finished the above washing, the powdery polymer was driedusing a vacuum line. Elemental analysis values of the resulting polymerwere found to be: 83.5% carbon, 4.0% hydrogen, 10.6% nitrogen and 0.03%bromine and almost agreed with calculated values (85.0% carbon, 3.9%hydrogen and 11.6% nitrogen) of a polymer comprising the recurringstructural unit represented by the following chemical formula (15)##STR7##

The difference between the found and calculated values seems to beattributable to the difficulty in achieving a complete combustion whenperforming the elemental analysis of the polymer, mainly due to a highheat stability of the polymer. The bromine content in the found valuesis conjectured to be attributable to unreacted terminal groups of thepolymers as shown in the following chemical formula (16): ##STR8##

In this example, the yield of the polymer was 95%.

The above polymer was soluble in formic acid and chloroform. Therefore,the molecular weight of the polymer was determined by means of the GPCor light scattering method with regard to a chloroform solution and aformic acid solution of the polymer, respectively. It was found that asthe result of the GPC, the polymer had a number-average molecular weightof 2,600 corresponding to a degree of polymerization of about 21, whileas the result of the light scattering method, the polymer had aweight-average molecular weight of 2,000 corresponding to a degree ofpolymerization of about 16.

In addition, the infrared absorption spectrum of the above polymershowed the below-described absorptions.

3,042 m, 1,613 s, 1,570 m, 1,539 s, 1,501 vs, 1,450 w, 1,368 m, 1,333 m,1,287 m, 1,253 m, 1,161 m, 1143 m, 1,022 w, 965 vs, 915 m, 870 w, 796 m,761 vs, 629 s, 461 w, 429 w, where the numbers indicate positions ofabsorption in a cm⁻¹ number, and w, m, s and vs mean weak absorption,medium absorption, strong absorption and very strong absorption,respectively. The above results of the measurements were obtained all ina KBr pellet.

Additionally, the UV to visible region spectrum of a formic acidsolution of the above polymer showed relatively sharp, clear andmountain-like maximal absorption peaks in the vicinity of about 370 and260 nm.

Furthermore, the above polymer exhibited a high heat-stability. As aresult of thermogravimetric analyses, a slight weight loss was observedfor the first time at about 300° C. Upon heating up to 900° C. innitrogen, the rate of the ignition loss was about 17% by weight.

EXAMPLE 5

A 0.3 mmol 1,4-dibromoisoquinoline, a 0.15 mmoltris(2,2'-bipyridine)nickel salt [Ni(bpy)₃ Br₂ ] and a 3.75 mmoltetraethylammonium perchlorate [(C₂ H₅)₄ NClO₄)] were dissolved in a 15ml N,N-dimethylformamide to prepare an electrolyte. This electrolyte wasintroduced into an electrolytic cell equipped with platinum plates (1cm×1 cm=2 cm²) as a cathode and an anode and a silver electrode as areference electrode. Then, an electrolytic polymerization reaction wasconducted for 16 hours at a polymerization temperature of 60° C. and anelectrolytic potential of -1.7V (a potential vs Ag/Ag⁺, the same applieshereinafter) and a yellow, filmy polymer (isoquinoline-1,4-diyl polymer)was produced on the cathode. This filmy polymer was collected and then,in order to remove impurities such as nickel compounds or the liketherefrom, washed several times each with the under-enumeratedsubstances (a)-(f), sequentially in this order.

(a) a 29% ammonia aqueous solution,

(b) methanol,

(c) a sodium ethylenediamine tetraacetate hot aqueous solution, adjustedto pH 3,

(d) a 29% ammonia aqueous solution,

(e) hot water, and

(f) methanol.

After having finished the above washing, the filmy polymer was driedusing a vacuum line. This polymer showed the below-described absorptionsin the infrared absorption spectrum thereof.

3,048 m, 1,614 s, 1,571 m, 1,543 s, 1,504 vs, 1,449 w, 1,372 m, 1,333 m,1,283 m, 1,254 m, 1,161 m, 1144 m, 1,024 w, 965 vs, 914 m, 870 w, 796 m,763 vs, 629 s, 462 w, 425 w, where the numbers indicate positions ofabsorption in a cm⁻¹ number, and w, m, s and vs mean weak absorption,medium absorption, strong absorption and very strong absorption,respectively. The above results of the measurements were obtained all ina KBr pellet.

Additionally, the UV to visible region spectrum of a formic acidsolution of the above polymer showed relatively sharp, clear andmountain-like maximal absorption peaks in the vicinity of about 370 and260 nm.

These spectrum data show that the obtained yellow filmy polymer is thesame as the polymer obtained in Example 4 that has a recurringstructural unit as shown in the chemical formula (15).

EXAMPLE 6

Degrees of depolarization of formic acid solutions respectively of thequinoline-5,8-diyl polymer obtained in Example 1 and quinoline-4,7-diylpolymer obtained in Example 2 were determined by means of the lightscattering method using a laser beam. In the degree of depolarization ρ,the ρ_(v) value is related with a polarizability (α₁) in the directionof the longitudinal axis of the polymer and a polarizability (α₂) in thedirection of the lateral axis of the polymer, according to the followingformulae (17) and (18): ##EQU1##

Therefore, in the condition of α₁ >α₂, δ² =1 and ρ_(v=1/3).

The quinoline-5,8-diyl polymer obtained in Example 1 andquinoline-4,7-diyl polymer obtained in Example 2 showed ρ_(v) values ofat least 0.33 and at most of 0.01, respectively. Thus, the fact that thequinoline-5,8-diyl polymer has a very large ρ_(v) value demonstrates avery large polarizability (α₁) along the main polymer Chain and thussuggests that the polymer takes a rod-like, linear structure. Incontrast, the fact that the quinoline-4,7-diyl polymer has a very smallρ_(v) value demonstrates substantially no difference exist between thepolarizability (α₁) in the direction of the longitudinal axis and apolarizability (α₂) in the direction of the lateral axis of the polymerand thus suggests that the polymer takes a random coil structure.Additionally, all the ρ_(v) values were determined with a formic acidsolution of the polymer.

EXAMPLE 7

A chloroform solution of the isoquinoline-1,4-diyl polymer obtained inExample 4 was spread over a platinum plate and chloroform was removed byevaporation to provide a polymer film. A cyclic voltammogram of thispolymer film was determined in an acetonitrile solution containing (C₂H₅)₄ NClO₄ in an amount of 0.1 mol/1. As a result, it was found thatthis polymer could be doped at about -2.1V vs Ag/Ag⁺ and undoped atabout -2.0V (potential vs Ag/Ag⁺ ) by a reverse sweep. During doping,the color changed from pale yellow to reddish purple, while duringundoping the color changed reversely. Such electrochemical behaviors andcolor changing phenomena indicate that the polymer of the presentinvention is electrochemically active and suited for use as componentsof cells such as electrodes for batteries as well as materialsexhibiting electrochromism.

The doping and undoping potentials obtained by the isoquinoline-1,4-diylpolymer of the present invention were substantially on the same level asthose obtained by polypyridine-2,5-diyl. Since the polypyridine-2,5-diylis a typical compound n-type dopable at this potential and has aπ-conjugation system basically analogous to that of the polymers of thepresent invention, it is assumed that n-type doping is performed also inthe above electrochemical doping.

Further, when the isoquinoline-1,4-diyl polymer according to the presentinvention was soaked in a solution containing sodium naphthalide (areaction product of naphthalene and sodium), the same color change frompale yellow to purple or reddish purple as in the case ofelectrochemical doping was observed. It was found that a solid materialobtained by compression molding a sodium ion adduct of the producedisoquinoline-1,4-diyl polymer under pressure was a semiconductor havingan electroconductivity of 1.8×10⁻³ Scm⁻¹ (siemens·cm⁻¹) at roomtemperature. Sodium naphthalide is a typical compound to dope highpolymers of π-conjugation system into n-type conductors, so that it isassumed that n-type doping is performed the same as the above-describedelectrochemical doping.

Since they ar resistant to heat and soluble in organic solvents, the(iso)quinolinediyl polymers according to the present invention can beshaped into fibers, films or the like, according to a dry process bymaking use of solutions obtained by dissolving in an appropriate organicsolvent which is evaporated after shaping. Besides, the polymers of theinvention have excellent characteristics such that the degree ofdepolarization and electrochemical oxidation-reduction potential arecontrollable according to the polymer structure, etc. which have notbeen realized by conventional polyarylenes.

Alternatively, according to the process of the present invention, bondpositions of monomers can be exactly decided, since these correspond tothe location of bonded eliminating groups i.e. halogen groups.Therefore, various (iso)quinolinediyl polymers differing in bondposition can be arbitrarily synthesized. Namely, FIG. 1 shows the IRspectra of polymers (a), (b), (c) and (d) manufactured from5,8-dibromooquinoline, 4,7-dichloroquinoline, 1,4-dibromoisoquinolineand 5,8-dibromoisoquinoline, respectively, in accordance with theprocess of Example 1 described above. In all these spectra, thoughabsorptions characteristic of condensed heterocyclic rings, i.e., an(iso)quinoline rings, are recognized, the absorption peaks based on C-Hout-of-plane deformation vibration and stretching vibration differlittle by little. These peaks well agree with the spectrum of eachmonomer.

Additionally, the obtained polymers are all soluble in formic acid,chloroform or the like, and the peaks characteristic of the protons ofthe (iso)quinoline rings are observed over 7-10 ppm in the ¹ H-NMRspectrum of each polymer. Alternatively, also in the ¹³ C-NMR spectrum,the peaks characteristic of the aromatic carbons of the (iso)quinolinerings are observed over 120-160 ppm. FIG. 2 shows the ¹³ C-NMR spectrumof the quinoline-4,7-diyl polymer. From these results, it is understoodthat (iso)quinolinediyl polymers whose bond positions have beencontrolled can be obtained.

What is claimed is:
 1. A process for preparing an (iso)quinolinediylpolymer comprising, as a recurring structural unit, a divalent grouprepresented by the following chemical formula (1) or (2): ##STR9##wherein n is an integer of at least 5, which process comprises reactingan (iso)quinoline dihalide represented by the following general formula(3) or (4): ##STR10## wherein X represents a halogen atom, with azero-valent nickel compound.
 2. A process for preparing an(iso)quinolinediyl polymer comprising, as a recurring structural unit, adivalent group represented by the following chemical formula (1) or (2):##STR11## wherein n is an integer of at least 5, which process compriseselectrolytically reducing an (iso)quinoline dihalide represented by thefollowing general formula (3) or (4): ##STR12## wherein X represents ahalogen atom, in the presence of a nickel compound.